1. Field of the Invention
This invention relates generally to medical devices. More particularly, this invention relates to hemostatic devices used to seal blood vessel punctures or incisions.
2. State of the Art
A wide variety of intravascular procedures involve the insertion of various medical instruments, such as catheters and other surgical instruments and devices, into an artery. For example, in the treatment of vascular disease, balloon catheters and the like are typically inserted into the artery to perform procedures therein. To carry out such procedures, an opening is generally formed in the affected artery or at a peripheral location (such as the femoral artery).
After the procedure has been completed, bleeding through the arterial opening must be stopped. Traditional methods for closing the arterial opening involve sutures, clamps and/or the application of prolonged manual pressure to the puncture site. Alternative devices have been proposed. For example, U.S. Pat. No. 6,547,806 to Ding describes the use of a collapsible sealing member including a fluid-impervious film carried by a shape-resilient wire structure. The sealing member is housed within a sheath. The sheath (and the sealing member therein) are inserted to/through the arterial opening, and the sealing member is deployed from within the sheath into the interior region of the artery. During deployment, the sealing member expands into its naturally expanded configuration. The sealing member is then securely positioned against the inner wall of the artery adjacent the opening in the artery. Sealant (in flowable form, gel, solid, or paste) is then delivered to the tissue leading to the arterial opening. Depending upon the sealant used, it is necessary to wait a period of time (or provide appropriate light for a photo-initiated material) before the sealant forms a hemostatic closure. When the sealant is ready, the sealing member is removed from the artery by repositioning the sealing member back into the sheath, and retracting the sheath (and sealing member therein) from the artery through the sealant. A small opening may remain along the path where the device is withdrawn. Compression or a surgical suture may be used to close this small opening. This device has numerous drawbacks, including the wait-time (or the additional steps) required for the sealant to form a hemostatic closure as well as the delay and associated problems in closing the small opening that remains upon withdrawal of the device.
Another device is described in U.S. Pat. No. 6,171,329 to Shaw et al. It includes a distal sealing membrane and proximal sealing membrane disposed within a delivery catheter. Both sealing membranes are formed from a single elastic wire shaped into two helical support structures with an eyelet therebetween. Multiple layers of a PTFE film are formed on the two helical support structures. Deployment of the device is accomplished by inserting the delivery catheter with the two sealing members therein through the tissue opening and forcing the distal sealing member out of the delivery catheter to enable the distal sealing member to expand to its deployed shape. The delivery catheter is then withdrawn from the tissue opening, and the proximal sealing member is forced out of the delivery catheter to enable the proximal sealing member to expand to its deployed shape. A latch portion of the wire is used to secure the two sealing members in place. This device has numerous drawbacks. For example, because the device is formed from a single wire, the positions of the two sealing members relative to one another are fixed. Thus, it cannot readily conform to (and seal) tissue openings of varying wall thickness. Moreover, the operator manipulates the single wire in deploying both the distal sealing member and the proximal sealing member and thus risks inadvertent retraction of the distal sealing member through the tissue opening and damage thereto.
Thus, there remains a need in the art for an improved hemostatic closure device that provides for efficient and effective closures of vascular openings in arteries or other blood vessels.